This invention relates to breastpumps for drawing breastmilk, and particularly to a motorized, such as electrically driven, breastpump.
Breastpumps for use by nursing mothers are well known. They allow the nursing woman to express the breastmilk as necessary or convenient, and further provide collection of the breastmilk for later use. For some mothers, breastpumps may be a necessity, such as when the child has suckling problems, or if the mother has problems with excessive or deficient milk production, or soreness, deformation or injury of the mammilla.
Manual breastpumps are commonplace, primarily because they are relatively inexpensive and easy to transport. Being manually driven, however, stroke rate and suction pressure produced can be uneven, and operating the pump can ultimately be tiring.
Electrically-driven breastpumps are also commonplace. They may be of a substantially large size of a non-portable or semi-portable type, typically including a vacuum pump which has an electric motor that plugs into standard house current. Advantages of this type of pump are ready controllability and regulation of the vacuum, and the ability to pump both breasts at once. That is, the nursing woman has both hands free to hold two breastpump shields in place for pumping of both breasts at the same time.
Battery-driven breastpumps have also been developed. These breastpumps have the advantages of controllability and regulation of the vacuum, as well as being easily carried. Such a battery-driven portable breastpump is described in U.S. Pat. No. 4,964,851, for example. This breastpump, sold under the name MINIELECTRIC by Medela, Inc., is lightweight and achieves good vacuum (i.e., negative pressure) regulation in preferred limits, for example, between about 100 and about 220 mmHg. The LACTINA breastpump sold by Medela, Inc. is also another type of breast pump which may be driven by battery as well as house current. It is generally disclosed in U.S. Pat. No. 5,007,899.
Electrically driven motorized breastpumps have almost universally been developed with a single type of xe2x80x9ccyclexe2x80x9d for a given pump. That is, the driving mechanism for generating the vacuum (negative pressure) to be applied at the breast in the more sophisticated pumps is geared to a particular sequence, or curve, of negative pressure increase (i.e., increasing suction), and then release. This is often aimed at reproducing in some sense the suckling action of an infant, for instance. Breastpumping can cover a range of different conditions, however, such as where the mother""s nipples are sore for some reason, there is a state of significant engorgement, some nipple stimulation may be particularly desired, let-down and relaxation may be of particular interest, it may be desired to increase milk production, and so on.
Some breastpumps provide the user with the ability to vary the amount of vacuum being applied, as well as the speed of the pumping action (i.e., number of cycles per minute). In some instances in the prior art, speed and vacuum level may influence each other, such that as speed increases so does the vacuum level. The basic xe2x80x9ccurvexe2x80x9d remains fixed, however, and the user must adapt as best she can to making variations within that particular curve built into the machine, which typically has been generalized for the overall population of users.
It is a principal objective of the present invention to provide a breastpump which can be programmed to generate, among other things, a plurality of differing milk expression (extraction) sequences, or curves. To this end, the invention in one form is a breastpump comprising a breastshield having a portion within which a woman""s breast is received for the expression of milk. A source of vacuum is in communication with the breastshield. There is a mechanism for operating the source of vacuum according to a first sequence, and a controller for operating the source of vacuum according to a second sequence.
The controller can have a preset program for the second sequence which is a milk letdown sequence, for example. Preferably, the breastpump has a plurality of different programs for the controller wherein each program has a different sequence.
In one embodiment of the invention, a motorized pump (e.g., compressed air, battery and/or house current) is provided with a microprocessor-based controller. Cards, with memory xe2x80x9cchips,xe2x80x9d containing different suction curves adapted for varying conditions and objectives are included for programming the controller in this embodiment. A user selects a desired program, and that card is then read by a mechanism providing input to the controller. It should be noted that while suction curves are generally addressed in the first instance herein, the milk expression sequences may also include a positive pressure aspect. The programming could also be provided via other media, including discs, CDs, infrared data transfer, electronic feed (e.g., an Internet connection), and so forth.
A significant, and heretofore unavailable advantage realized by the present invention is the ready ability to modify the breastpump suction action to a variety of desired conditions, and provide this ability to the end-user. An attendant advantage is that, as the science of breastpumping continues to make advances, new and improved suction curves and sequences can be made available on further cards, or other program-inputting means.
Yet another attendant advantage is that the programmable pump can also record data relating to its use and operation. That data could be stored, for instance, and then retrieved as by downloading through an Internet connection, magnetic recording (disk or card), and the like. This data retrieval would be useful in medical research, for updating the pump with new data, for monitoring usage, just for some instances.
Further, a program could be made of a particular infant""s suckling pattern. That program could then be used to operate the pump, and then varied over time as the infant grows.
In yet another aspect of the invention, an improved breastpump is provided which has a pre-programmed milk let-down sequence. The let-down sequence is most advantageously made available through a button or the like provided on the breastpump used to actuate the sequence.
In still another aspect of the invention, a breastpump includes an electric motor having a reduction gear system with at least first and second belts conveying motive power to a movable member of an expansible chamber device wherein a vacuum is generated. The expansible chamber device is, in one embodiment, a pair of diaphragm pumps. Each diaphragm pump has a membrane which is movable relative to a shell, each said membrane being connected to a respective drive shaft, each shaft being mounted to a respective belt for linear movement with the respective belt.
The present invention in another significant aspect has as an objective to provide a breastpump with one or more novel suction sequences which are considered to produce advantageous particularized results. Such sequences include, but are not limited to: a suction method (e.g., program or curve) for a sore nipple condition; a suction method for increased milk production; an improved suction method in general; and a method for nipple stimulation.
A method for operating a breastpump for a sore nipple condition according to the present invention comprises varying the amount of vacuum within a range of from about 20 mmHg (the least vacuum) to about 250 mmHg (the greatest vacuum) while simultaneously varying the overall suction cycle from about 25 cycles/min. at the least vacuum to about 40 cycles/min. at the greatest vacuum, such that for a lower vacuum applied there is an increase in the number of cycles. In general, this program is intended to provide a lower peak vacuum over a longer cycle.
A method for operating a breastpump which is considered to yield an increase in milk output according to the present invention comprises operating the pump at a rapid cyclical rate on the order of about 120 cycles/min., with a negative pressure in the range of about 50 to about 150 mmHg. This method further preferably includes a pause after each period of vacuum application, such as applying the vacuum for about ten seconds of vacuum, with then a two second pause.
A method for operating a breastpump according to yet another aspect of the invention comprises varying the vacuum within a range of about 100 (the least vacuum) to about 250 mmHg (the greatest vacuum), while simultaneously varying the overall suction cycle from about 47 cycles/min. at the greatest vacuum to about 78 cycles/min. at the least vacuum, such that for a lower vacuum applied there is an increase in the number of cycles, with a cycle following a curve which initially builds to a peak negative pressure, then smoothly starts a pressure increase (less negative) along an initial slope but then slows the pressure increase briefly, before continuing on essentially said initial slope for the negative pressure release.
A still further aspect of the present invention is a unique breastpump assembly having features including: a compact housing design and breastshield carrying casing; and a double-diaphragm pumping mechanism.
A prophylactic device for protecting the diaphragm from fluid (air/milk) is additionally provided. In one embodiment of this aspect of the invention, a diaphragm pump for a breastpump comprises a shell having a generally hemispherical interior shape with a flexible membrane movable within the hemispherical shape to expand and contract a volume created in a chamber defined between the membrane and the shell. A mechanism connected to the membrane, such as a puller, moves the membrane to expand and contract the volume. A port is provided in the shell through which air moves in response to expansion and contraction of the volume, such that vacuum can be communicated to a breastshield through connection to the port.
A removably mounted flexible cover is located between the shell and the membrane which isolates the membrane from fluid. The cover is removable for at least one of cleaning and disposal. To that end, the flexible membrane has a circumferential rim upon which the cover is received over the rim. The shell has an internal opening defined therein sized to encompass the rim with the cover mounted on the rim in a substantially airtight fit. The cover thereby forms a gasket between the rim and shell. A one-way valve extending through the membrane is additionally provided, allowing exhaustion of air between the membrane and cover.
Yet another significant aspect of the present invention is considered to be a manually operated control, such as a rotary knob, which is used to simultaneously adjust the suction level as well as rate within a sequence. In this aspect of the invention, the suction xe2x80x9cforcexe2x80x9d and xe2x80x9cspeedxe2x80x9d are tied together in an inverse relationship. As the suction force (vacuum) is increased, for example, the rate (cycle) is decreased; as the vacuum is decreased, the cycle increases.